Air cooling means for internal combustion engines



June 2411941.

K. LGHNER AIR COOLING MEANS FOR INTERNAL COMBUSTION ENGINES Filed Nov. 1, 1959 3 Sheets-Sheet l June 24,1941.

K. LOHNER AIR COOLING MEANS FOR INTERNAL COMBUSTION ENGINES 3. She etS -Sheet 2 Filed Nov. 1, 193a INVENTOR Kan [dither BY ATTORNE June 24, 1941. K. LOHNER I AIR COOLING MEANS FOR INTERNAL COMBUSTION-ENGINES Filed Nbv. 1, 1938 3 Sheets-Sheet 3 INVENTOR Kari [071/167 a Q ATTORNEY Patented June 24, 1941 UNITED STATES PATENT OFFICE AIR COOLIKTG MEANS FOR INTERNAL COM- BUSTION ENGINES Kurt Liihner, Munich, Germany, assignor to the firm: Bayerische Motorcn Werke Aktiengesellschaft, Munich, Germany Application November 1, 1938, Serial No. 238,136 Germany March 4, 1936 6 Claims.

This invention relates to air cooling means for internal combustion engines, and more particularly to engines having two or more rows of multiple cylinders either parallel to one another, at an angle to one another, or arranged as a radial engine.

An object of this invention is to provide an improved arrangement for cooling the cylinders by the use of simple guiding means, the amount I of cooling air available to the cylinders of an internal combustion engine having two or more rows of multiple cylinders, as compared with the arrangements now known to the art.

A still further object of this invention is to provide an arrangement for the cooling of an internal combustion engine having two or more rows of multiple cylinders, whereby the entire cross-sectional surface both at the front and at the rear of the engine is used on the one hand for the inflow and on the other hand, for the outflow of the cooling air, whereby the quantity of air which is passed over the cylinders is twice that used with previous methods of guiding the cooling air.

A more specific object of this invention lies in the provision of obliquely extending guide plates forming partitions between the rows of an internal combustion engine having two or more rows of multiple cylinders, to form alternate canals for cooling the heads and feet of such cylinders.

Generally speaking, this invention may be defined as comprising the constructions and combinations recited in the annexed claims and illustrated in certain embodiments in the drawings accompanying and forming a part of this application, wherein:

Fig. 1 is a diagrammatic plan view of an internal combustion engine having a plurality of rows of multiple cylinders, indicating the novel cooling arrangement for said cylinders in accordance with the principles of this invention; a

Fig. 2 is a diagrammatic transverse view between the cylinder rows illustrating the path of the cooling and heated air flow as a result of my improved construction Fig. 3 is a flat, developed cross-sectional view along the line ABC of Fig. 4 illustrating a preferred embodimentof the invention as applied to' a V-engine having two rows of cylinders;

Fig. 4 is a transverse cross-sectional view along the lines D-E of Fig. 3;

Fig. 5 is an end view of the cylinder and cooling canal arrangement shown in Fig. 3, as seen in the direction of the arrow I;

Fig. fi'is an end view of the cylinder and cooling canal arrangement illustrated in Fig. 3, as seen in the direction of the arrow II; and

Fig. 7 is a longitudinal cross-sectional view .along the line F-G of Fig. 6.

In order that. the principles of this invention may be more clearly understood, reference is made to Fig. 1 illustrating diagrammatically an internal combustion engine having three rows of three cylinders each. It will be immediately apparent from a study of this figure that full utilization ismade of the spaces between the rows of cylinders andalongside the outside rows of cylinders for supplying cooling air to and conducting heated air away from the cylinders, while at the same time each cylinder is completely cooled from head to foot. Cooling air entering the space between the first and second rows of the cylinders, as seen from the left to right and indicated in solid lines, will separate to cool the upper portion of each cylinder in these two rows. The air entering the space between the second and third rows of cylinders, counting in the same direction, will separate to cool the foot portions of the cylinders. The air stream cooling the upper portions of the cylinders are indicated in solid lines, while those cooling the foot portions of the cylinders are indicated in dashed lines. At the same time, the feet of the first row of cylinders will .be cooled by the air stream entering at the extreme left, while the heads of the third row of cylinders will be cooled by the air stream entering at the extreme right. Since the head and foot air streams are diverted across the cylinders, such air streams will cross one another so that the rear space between the first and second row of cylinders will be completely utilized for the hot outgoing airfrom the feet of the cylinders and that between the second and third row for hot outgoing air from the heads of the cylinders.

This arrangement is brought about by providing inclined partitions between each cylinder row and V at the sides of these cylinder rows, the partitions first and second rows of cylinders in solid lines, and the heated air directed beneath this partition from the side in dashed lines. The partition extending reversely to the first partition and positioned between the second and third rows is also indicated in dashed lines. Fig. 2 illustrates the manner in-which the arrangement according to the present invention, in contrast to those of the prior art, fully utilizes the space between the cylinder rows for the incoming cold air and the outgoing heated air. It will .be noted that ,by such an arrangement, despite the fact that the air is diverted across the cylinders to insure complete and eflicient cooling, that the total crosssectional path is maintained from the time the stream or streams 'of air enter until such time that they leave at the rear of the engine. Ac-

cordingly, a more'eflicient use of the cooling air is realized.

It will be obvious to those skilled in this art that the principles of the above described con-' struction can be utilized for any number of rows of cylinders no matter how they are positioned. It is equally adaptable for V-engines, double V-engines, radial engines, and the like.

A preferred practical embodiment of the principles of this invention is illustrated in Figs. 3 to '7 inclusive, showing the invention adapted to an inverted V-engine havingtwo rows of multiple cylinders. In the space between the cylinder rows there is provided a plate- I, rising upwardly from the front to the rear of the cylinder rows 8 and 9 and forming a dividing partition in the space between such cylinder rows. In the example shown where there are only two rows of cylinders, a covering sheet II will be provided about these row's, spaced from the outer side of each row and from the cylinder heads. Between the outside of the cylinder rows and the inner wall of the casing, there are positioned additional plates 2 and 3 which will preferably extend obliquely from the rear to the front in a direction opposite to that of the plate I.

The central dividing plate I may be attached and held in place through the cooling fins on opposite cylinder rows, the construction being preferably such that the cooling fins on the cylinders at the juncture between the cylinder heads and feet will be extended and attached to the plate I in any suitable manner. Similarly, the plates 2 and 3 will be attached in any suitable manner along their outer sides to the covering 'sheet I I and at their inner sides to the extended fins on the cylinders at the points between the cylinder heads and feet.

By means of the foregoing arrangement there will be provided a central rising air passage for the, cooling air for the cylinder feet, decreasing in size in the direction from front to rear. Similar passages atthe sides of the cylinder rows for the cooling of the cylinder heads are provided by the obliquely positioned plates 2 and 3. However, it is to be noted that as the cooling air entering, for example, the central passage formed by the plate I, passes about the individual cylinders of the rows 8 and 9, being forced substantially in this direction by the damming up of the air at the end of the passage, such air after passing about the cylinders will flow into a passage of gradually increasing size formed above the outer plates 2 and 3. Thus, for example, with respect to the cooling at the cylinder feet, as the number of cylinders to be cooled become less, the cooling canals formed between the cylinder rows beheated air coming from about the cylinder heads increases, the size of the discharge canals for such heated air gradually increases. Thus, the oncoming central air stream will first enter the space I4, of gradually decreasing size, will split into the separate streams 4 and I and the heated air will exit through the gradually increasing spaces I3 and I6.

On the other hand, the streams 5 and 6 for cooling the cylinder heads, because of the gradually decreasing size of the spaces I5 and II, will be forced inwardly about the cylinder feet and will exit into the space I2, gradually increasing in size.

For guiding the flow of air about the individual cylinders, there are preferably provided air guide columns III, as clearly indicated in Figs. 3 and 7.

Attention is directed to the fact that as the sides of the plate I will remain at the same level, i. e., at the point between all of the cylinder heads and feet, while the plate itself rises from front to rear, the plate as a whole will be bent for the greater part of its length as seen, for example, in Fig. 4. This resulting bending assists in dividing the oncoming air stream and directing it over the cylinder rows Theplates 2 and 3, since they are always at the same level at their inner sides will also be given a bent configuration, the amount of bend varying along their respective lengths.

Instead of attaching the air-guiding and di viding plates to extended cooling fins on the cylinders, other suitable arrangements for positioning and holding these plates in the desired manner may be used, as will be obvious to those skilled in this art.

It will also be clear that while the direction of oncoming cooling air has been indicated in Fig. 3 in the direction of the arrow II, whereby the central column of air cools the cylinder feet and the side columns of air cool the cylinder heads, the arrangement will work just as well if the air comes from the opposite direction in which case, however, the central column of air would cool the cylinder heads, while the side columns of air would cool the cylinder feet.

While the invention has been illustrated as applied to an engine of the inverted V-type, consisting of only two rows of cylinders, it is obvious that it is also easily applicable to an engine of the radial type, in which case the guiding plates between the cylinder rows would all be of the same size but would extend obliquely in alternate direction. In the present case, or in any case where the radial type of engine is not used, each passage formed between the outside of the cylinder rows and the surrounding covering will have approximately half the area of the passages between the cylinder rows, so that there will be substantially the same amount of air for cooling the cylinder heads as for .the cooling of the cylinder feet. Likewise, the total cross-sectional area of the passages for the oncoming air will be equal to the total cross-sectional area of the passages for the outgoing heated air. This is true because of the fact that while the passage or space I4 for the oncoming cooling air between the rows of I cylinders decreases due to the upwardly extending come gradually smaller, while as the amount of plate, at the same time in an equal manner the .side passages or spaces I3 and I6 for the heated air increase so that the cross-sectional area of the outlet for the separate streams of air 4 and I is equal to the cross-section of the combined oncoming stream of cooling air entering between the cylinder rows. In a similar manner, while the passages or space l and I! for the individual cooling air streams 5 and 6 of the cylinder heads decrease due to the descending size partitions 2 and 3, the combined streams of heated air 5 and 6 will exit through a passage which is gradually increasing, so that the final area of exit is equal to combined cross-sectional areas of the partial entrances at the sides of the cylinder rows. In this manner, applicant utilizes the entire front and rear spaces about the cylinder rows, thereby procuring the greatest possible air stream for cooling purposes.

It will be noted that the construction shown and described above will serve admirably to accomplish the objects stated. It is to be understood, however, that the construction disclosed is intended merely as illustrative of the invention and not as limiting, as various modifications thereof may be made without departing from the invention as defined by a proper interpretation of the claims which follow:

1. In an internal combustion engine having two rows of cylinders spaced apart from one another, a partition positioned between the cylinder rows, said partition extending obliquely from the lower end of said cylinders at one end of the rows to the upper end of, said cylinders at the other end of said rows, a covering spaced from and surrounding the two cylinder rows about the cylinder heads and outer sides, and a pair of further partitions, one positioned between the outer side of each cylinder row and said surrounding covering, said partitions each extending obliquely from the upper end of the cylinder at one end of its row to the lower end of the cylinder at the other end of its row in a direction opposite to that of the partition intermediate said cylinder row, whereby the cold air approaching one end of said cylinder rows is divided into one large central stream cooling the heads of said cylinders, which stream is separated into two oppositely directed streams of hot air leaving the other end of the cylinder rows on the outside thereof, and two small outside streams cooling the feet of said cylinders and directed inwardly beneath said first stream to form a single stream streams of air.

3. The combination according to claim 1 in which the cylinder rows are mounted obliquely to one another.

4. The combination according to claim 1, in'

which the longitudinal edges of said partition intermediate the cylinder rows are respectively interconnected with the cylinders of each row at the juncture between the cylinder heads and feet, and the side partitions each having their inner longitudinal edges respectively connected to the outer sides of the cylinders of each row at the juncture between the cylinder heads and cylinder feet, whereby separate cooling canals for the cylinder heads and cylinder feet are formed.

5. In an internal combustion engine having a plurality of rows of multiple cylinders spaced apart from one another a partition mounted between adjacent cylinder rows, each partition having its longitudinal edges connected to the cylinders of its respectively adjacent rows substantially at the point of juncture between the head and foot of each cylinder while at the same time said partitions extend alternately in an oblique direction from the lower end of the cylinders at one end of the rows to the upper end of said cylinders at the other end of said rows, whereby the space between adjacent cylinder rows is divided vertically into head and foot cooling spaces and longitudinally into cooling chem-- nels of decreasing size and heated air channels of increasing size.

6. The combination according to claim 5, in combination with means connected directly about the cylinders of each row serving to connect the cooling channel between the cylinder rows with the heated air channels formed between the adjacent cylinder rows.

KURT 1.6mm. 

